A direct contact between astrocyte and vitreous body is possible in the rabbit eye due to discontinuities in the basement membrane of the retinal inner limiting membrane

Different from most mammalian species, the optic nerve of the rabbit eye is initially formed inside the retina where myelination of the axons of the ganglion cells starts and vascularization occurs. Astrocytes are confined to these regions. The aforementioned nerve fibers known as medullated nerve fibers form two bundles that may be identified with the naked eye. The blood vessels run on the inner surface of these nerve fiber bundles (epivascularization) and, accordingly, the accompanying astrocytes lie mostly facing the vitreous body from which they are separated only by the inner limiting membrane of the retina. The arrangement of the astrocytes around blood vessels leads to the formation of structures known as glial tufts. Fragments (N = 3) or whole pieces (N = 3) of the medullated nerve fiber region of three-month-old male rabbits (Orictolagus cuniculus) were fixed in glutaraldehyde followed by osmium tetroxide, and their thin sections were examined with a transmission electron microscope. Randomly located discontinuities (up to a few micrometers long) of the basement membrane of the inner limiting membrane of the retina were observed in the glial tufts. As a consequence, a direct contact between the astrocyte plasma membrane and vitreous elements was demonstrated, making possible functional interactions such as macromolecular exchanges between this glial cell type and the components of the vitreous body

Use of topical ketanserin for the treatment of ulcers in leprosy patients.

A comparative study was carried out in which 66 leprosy patients with ulcers were randomly divided in two groups of 33 patients each: Group A (experimental group) was treated with ketanserin gel (2%) and group B with clioquinol cream and/or Lassar paste during a three month period. At the end of the study, when ulcer sizes in the two groups were compared, the group treated with topical ketanserin showed superior results (p < 0.001 using Kolmogorov-Smirnov's test). We conclude that the drug is useful as coadjuavant treatment for healing ulcers in these patients.